This blog provides updated forecasts and comments on current weather or other topics

Monday, January 16, 2012

Major Snow Event

This is going to be brief...I will provide a more detailed view tonight.

I have just taken a look at the latest (18 UTC) NCEP (NWS) model runs, the U.S. and ECMWF ensembles, and the runs from major modeling centers (UKMET, CMC, etc). The trend is much more threatening for Wednesday and it appears that we will have a major, highly disruptive snow event.

The big question for days...the question on which the forecast depended on...was where the trough/low pressure would go. Head north of us, we get perhaps 4-8 inches of snow, followed by a few hours of rain and then the whole thing starts melting. The snow would start around 3-4 AM on Wednesday AM. This is the best case (if you don't like a crippling snow event)

But some models...some very good models...were taking the low farther south, which would extend the period of snow or prevent a turn over to rain altogether. The Canadian GEM and UKMET office were going this way. Then then NWS NAM for the 12 UTC (4 AM) run. In the 18 UTC run both the NAM and the NWS GFS (normally the best NWS model around her) is taking a more southern route. And the 15 UTC NWS SREF ensembleis doing the same thing (at least the ensemble mean). Ok, this is getting a bit techy..sorry.

The bottom line is that there is a serious threat on Wednesday of 8-15 inches of snow over the region, with a minimal turn over to rain. The biggest snowstorm in years. Anyway, before anyone goes out and buys a snowblower, lets see what tonight's runs show. If they continue this trend then Slushmageddon might be replaced by Snowmageddon. In almost any conceivable case, Wednesday morning is going to be very problematic for travel...I suspect there will be a lot of school cancellations and the like.

The main roads around Seattle are in very good shape now, but the Wednesday event could dwarf the weekend snow.

88 comments:

Yep, I've been seeing some of the same thing, keeping copious amounts of moisture rolling in, but also sucking down major cold air into a major snowstorm going most of Wednesday, and that's after a few more likely inches between now and Tuesday. NOAA and local forecaster looks like they're starting to push back the "change to rain" timing. NOAA is going with Wednesday night, meaning Wednesday is a loss for getting around.

Cliff ~ All the other news stations & blogs keep saying the "greater Seattle/Everett/Tacoma area" will be getting all of this snow, and some others say all of Western Washington.... I'm in Eatonville, and we usually warm up faster than anyone else, but is there heavy snow forcast for everyone, or is it going to stay in the Puget Sound area? Sorry, but it gets frustrating that the media forgets that Western Washington covers more area than just the greater Seattle area and north to Bellingham.....Thanks for your blog! I can always count on you for more precise and accurate information.....

You have a great blog here Cliff! I just moved from washington DC and was obsessed with the Capitol Weather gang blog that they have out there. I bet they are jealous of this potential "Big One" coming cant wait for more updates!

Yep, it's good to focus on the coming snow. But folks ought to simultaneously prepare for wind, rain and The Big Melt. All this water will need to go somewhere. Remember that storm 12 or 13 years ago, that dumped a foot of snow then immediately began dumping rain? Major flooding everywhere.

Sand bags are available at a number of Community Centers in Seattle. How's your sump pump working? Do you have a cracked foundation or leaky roof you need to keep an eye on? Are drains and downspouts clear? Are you prepared for power outages? Is your home unoccupied right now, and do you need to arrange for someone to check on it?

Looking back at comments posted barely two days ago, seems there may be crow on the menu for those who were so quick to criticize Accuweather and their long-lead prediction of a major winter storm for Seattle in this instance:

Blogger Cliff Mass Weather Blog said...

Well...Ilovewinter...that Accuweather "meteorologist" is really confused and clearly inexperienced with NW weather. In general, I would not believe an accuweather forecast...cliff

Wow...MORE?? Here in West Oly at 200ft elev. we have 6-8 inches already and it has been snowing hard since 1pm. Glad I stocked up on food at the store this morning... Any more information about wind accompanying this storm would be appreciated

I'm still on the fence whether I believe this will be a major storm wednesday and stick with snow.

With so much uncertainty between the model runs I have serious doubts.

Looking more short term, we are suppose to get 3 to 6 inches tonight (Monday Night) in my area (Spanaway). But even then the forecast for that storm seems to be uncertain as time gets closer to the event.

I've lived here long enough to know that I can't ever 100% trust the forecast for snow events, not even major ones.

The world shouldn't stop because we are looking at a record snowfall on Wednesday. Everyone now (thanks to our wonderful Cliff Mass and the National Weather Service among others) has ample warning to get prepared and plan with food, provisions for warmth as needed, and even transportation.

Hey folks, this is something that most of America experiences in a normal winter. Yet here (in my native Pacific NW), many think it is something that stops the world from spinning -- it doesn't.

Cliff, I just watched King5's Jeff Renner and then looked at NWS 3:30 forecast discussion and it looked like Renner was living in an alternative universe as to Wednesday's forecast. I look forward to your later blog tonight to find out if he's just betting the later model runs will keep him from having to panic the citizenry . . .

Who cares about the snow, I want to know if the dog sighting leads to anything positive! Cliff, I certainly hope this recent sighting means a well deserved homecoming for Leah. Especially in this cold weather. Thanks for your climate and weather updates.

Who cares about the snow, I want to know if the dog sighting leads to anything positive! Cliff, I certainly hope this recent sighting means a well deserved homecoming for Leah. Especially in this cold weather. Thanks for your climate and weather updates.

I do hope you get your dog back soon. I'm in Sequim yet I feel your loss and pain. There was never a purer love than that between man and his dog.You have been separated too long, it is time for itto come to a peaceful end. It will be so, I so will it.. Bill

Thank you for taking the time to let all of us neophytes what to expect. I look at the weather forecast on my homepage... and then I generally pop right over here to get the real scoop. You'ved saved our bacon a couple of times when big storms were forecasted and we were debating the merits of braving the pass.

I know this has nothing to do with Wednesdays "event", but do you have any input on what the system moving abruptly southward, just shy of Alaska's north shore, may or may not have impact on the system lolling in the Pacific at the moment. It seems as though the jet stream has been affected greatly by the low pressure system we are currently under, but if this arctic mass continues moving as quickly as it is, the potential for another "event" seems certain. I know once it hits landmass, it should slow down, and dissipate greatly, and forecast models can only anticipate what information is relative and on hand... but the way these two systems are behaving (the pacific, and the arctic) I think we may have more than anyone bargained for... http://www.weatheroffice.gc.ca/satellite/animateweb_e.html?imagetype=satellite&imagename=hrpt_canarc_ir_m_..................jpg&nbimages=1&clf=1

Heavens, Steve, some of the heaviest snowfalls I've seen were at temps above freezing. If you take an ice cube outside, does it melt instantly? No -- and snowflakes falling from cold air into warmer air don't melt instantly either.

Chiming in on the hopes that Leah will make it home to you. Perhaps the snowfall will lead her to mosey up to someone's door for a handout, or maybe leave tracks to help people find her. She has obviously got some hybrid vigor going on!!

The kids and I are planning on venturing up to the intersection where Leah was last spotted tomorrow morning, bright and early. With hamburger! (and sleds) since Seattle Public Schools are planning on being 2 hours late tomorrow. Can't wait to see if my wee ones can lure her to the car. Meantimes...not seeing any new snow in Lake Ciry. Even at this late hour, all is drippy, slushy, and melting fast! No smell of ozone that precedes Seattle snow. My hunch is that mañana brings very cold rain.